Image processing apparatus and method

Abstract

An image processing method is provided. The method includes detecting a number of consecutive occurrences of each image frame in a sequence of image frame inputs, wherein the sequence of image frame inputs includes at least one first image frame and at least one second image frame input sequentially, and image data of each first image frame is different from image data of each second image frame; determining a first lookup table according to a first number of consecutive occurrences of the at least one first image frame, wherein the first lookup table indicates a plurality of sets of compensation operations; and employing a first set of compensation operations of the plurality of sets of compensation operations according to a second number of consecutive occurrences of the at least one second image frame to process the image data of the at least one first image frame.

Description

TECHNICAL FIELD

[0001] The present invention relates to an image processing device and method, and more particularly to an image processing device and method for processing image signal cadence. BACKGROUND

[0002] When the cadence of an image signal is fixed, a display system can adjust image data of at least some frames in the image signal according to the cadence, and output the adjusted image signal to achieve better viewing quality. However, when the cadence of the image signal varies, the display system cannot adjust the image data in time to correspond to the varied cadence, and thus the output image signal can have stuttering or skipping, reducing the viewing quality. Therefore, reducing the drawbacks derived from the varied cadence has become one of the problems to be solved in the field. SUMMARY

[0003] An image processing method is disclosed, comprising the steps of: detecting a number of consecutive occurrences of each image frame in an image frame input sequence, wherein the image frame input sequence comprises at least one first image frame and at least one second image frame input in sequence, image data of each first image frame being different from image data of each second image frame; determining a first lookup table according to a first number of consecutive occurrences of the at least one first image frame, wherein the first lookup table indicates a plurality of sets of compensation operations; and using a first set of compensation operations in the plurality of sets of compensation operations according to a second number of consecutive occurrences of the at least one second image frame to process image data of the at least one first image frame.

[0004] An image processing device is disclosed, comprising a detector and a data processor. The detector is configured to detect a number of consecutive occurrences of each image frame in an image frame input sequence. The image frame input sequence comprises at least one first image frame and at least one second image frame input in sequence, image data of each first image frame being different from image data of each second image frame. The data processor is configured to determine a first lookup table according to a first number of consecutive occurrences of the at least one first image frame. The first lookup table indicates a plurality of sets of compensation operations, and the data processor is further configured to use a first set of compensation operations in the plurality of sets of compensation operations according to a second number of consecutive occurrences of the at least one second image frame to process image data of the at least one first image frame.

[0005] Compared with the prior art, the image processing device and method of the present invention sequentially detect the number of repetitions of each frame in the received image signal, and adjust the image data of the frames according to the detected number, to improve the smoothness of the output image and enhance the viewing quality. BRIEF DESCRIPTION OF DRAWINGS

[0006] Various embodiments of the present application can be best understood with reference to the following description and drawings. It should be noted that the various elements in the figures can not be drawn to scale. Indeed, the dimensions of some of the elements can be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals have been repeated among the figures to indicate corresponding elements.

[0007] Figure 1 A schematic diagram of an image processing device in some embodiments of the present application.

[0008] Figure 2 A schematic diagram of an image processing device in some other embodiments of the present application.

[0009] Figure 3 A schematic diagram of a lookup table in some other embodiments of the present application.

[0010] Figure 4 A timing diagram of image frame output in some other embodiments of the present application.

[0011] Figure 5 A flowchart of an image processing method in some other embodiments of the present application. DETAILED DESCRIPTION

[0012] Figure 1 A schematic diagram of an image processing device 10 in some embodiments of the present application. The image processing device 10 includes a detector 11, a register 12, a data processor 13, and a display 14. The image processing device 10 is configured to receive an image signal SV, and adjust the image signal SV according to a repetition number of image frames in the image signal SV to generate a display signal SD, and finally display the display signal SD using the display 14.

[0013] The image signal SV includes a plurality of image frames inputted in sequence. In other words, the image signal SV is composed of an image frame input sequence. The image frame input sequence includes a plurality of groups of repeated image frames. For example, as shown in FIG. 1, the image frame input sequence is in sequence of image frame Al, image frame A2, image frame Bl, image frame B2, image frame B3, image frame Cl, image frame C2, image frame C3, image frame Dl, and image frame D2 (for ease of expression, hereinafter denoted as Al, A2, Bl, B2, B3, Cl, C2, C3, Dl, and D2, respectively), wherein Al and A2 have the same image data. Similarly, Bl-B3, Cl-C3, and Dl-D2 have the same image data, respectively. Figure 2 The image frame input sequence shown in FIG. 1 is only an example, and the present application is not limited thereto. The image frame input sequence can also include a plurality of groups of image frames with various repetition numbers. Figure 2

[0014] ​The detector 11 is configured to receive the input sequence of image frames to detect the number of repetitions of the image frames having the same image data, and to write the detected number into the register 12. For example, Figure 2 For example, the detector 11 detects that A2 is the image frame having the same image data as Al and being consecutively input. Al and A2 having the same image data are repeated twice, and thus the detector 11 detects that the number of times corresponding to Al and A2 is 2, and writes 2 into the register 12. Similarly, the detector 11 writes 3, 3, and 2 into the register 12 to correspond to Bl- B3, Cl- C3, and Dl- D2, respectively.

[0015] In some embodiments, the detector 11 is configured to measure the average brightness of each image frame to detect the number of repetitions. When the average brightness of each of two adjacent image frames is substantially the same, the detector 11 determines that the two adjacent image frames are two adjacent image frames having the same image data. When the average brightness of each of two adjacent image frames is different, the detector 11 determines that the two adjacent image frames are two adjacent image frames having different image data.

[0016] In some embodiments, the register 12 is a queue register or a first-in-first-out (FIFO) register, and includes storage units Nl- N4. Figure 2 In the example shown, the register 12 sequentially stores 2, 3, 3, and 2 into the storage units Nl- N4. The number of storage units Nl- N4 of the register 12 is only an example, and the present application is not limited thereto.

[0017] The data processor 13 is configured to adjust the image signal SV according to the number of repetitions detected by the detector 11. When 2, 3, 3, and 2 are stored into the storage units Nl- N4, respectively, Al- A2, Bl- B3, Cl- C3, and Dl- D2 correspond to the number of times of the storage units Nl- N4, respectively.

[0018] The data processor 13 adjusts Al- A2, Bl- B3, Cl- C3, and / or Dl- D2 according to the number of times stored in the storage units Nl- N4. The data processor 13 includes a memory 131 configured to store a plurality of lookup tables LTl- LT3 (see also FIG. 2). The data processor 13 is configured to adjust Al- A2, Bl- B3, Cl- C3, and / or Dl- D2 according to the number of times stored in the storage units Nl- N4 by referring to the lookup tables LTl- LT3. Figure 3The lookup tables LT1 to LT3 are used to indicate multiple sets of compensation operations MC11 to MC13, MC21 to MC23, and MC31 to MC33, respectively. Each of the lookup tables LT1 to LT3 corresponds to a different first index value i1, and each lookup table LT1 to LT3 also corresponds to multiple different second index values ​​i2. The data processor 13 determines one of the lookup tables LT1 to LT3 based on the number of times the storage units N1 to N4 are stored and the first index values ​​i1, and then determines one of the compensation operations based on the second index values ​​i2 in the determined lookup table to adjust A1 to A2, B1 to B3, C1 to C3 and / or D1 to D2.

[0019] In some embodiments, after the data processor 13 finishes processing a set of recurring image frames, the storage unit in register 12 that stores the number of repetitions is cleared. For example, after the data processor 13 finishes processing A1 to A2, the data in storage unit N1 in register 12 is cleared.

[0020] in accordance with Figure 2 Taking data processor 13 processing B1 to B3 as an example, in some embodiments, data processor 13 determines which lookup table and which set of compensation operations to use to process B1 to B3 based on the number of repetitions stored in storage units N2 and N3. First, the repetition count corresponding to B1 to B3 is 3 and is stored in storage unit N2. After reading storage unit N2, data processor 13 determines lookup table LT3 with the first index value i1 being 3 as the lookup table to be used. Next, data processor 13 reads storage unit N3 (with a repetition count of 3) and uses compensation operation MC33 corresponding to the second index value i2 being 3 in lookup table LT3 to process B1 to B3. In other words, data processor 13 first determines lookup table T3 corresponding to the first index value i1 that matches the number of repetitions stored in storage unit N2, and then determines compensation operation MC33 corresponding to the second index value i2 that matches the number of repetitions stored in storage unit N3.

[0021] In some embodiments, compensation operations MC11-MC13 are different from each other, compensation operations MC21-MC23 are different from each other, and compensation operations MC31-MC33 are different from each other. Different compensation operations represent different image processing methods. When the number of repetitions of B1-B3 is 3 and the number of repetitions of C1-C3 is 3, the data processor 13 selects the compensation operation MC33 in the lookup table LT3 to process B1-B3; and when the number of repetitions of C1-C3 is 3 and the number of repetitions of D1-D2 is 2, the data processor 13 selects the compensation operation MC32 in the lookup table LT3 to process C1-C3. Because the number of repetitions of C1-C3 (3) is different from the number of repetitions of D1-D2 (2), the way the data processor 13 processes B1-B3 is different from the way it processes C1-C3. In other words, the way the image signal SV is processed by the data processor 13 is related to the number of repetitions of the image frame with the same image data that is being processed and the number of repetitions of the image frame with the same image data that will be processed next.

[0022] In some embodiments, the number of lookup tables LT1 to LT3 stored in memory 131 is limited. Therefore, when the number of times a detected image frame is repeated exceeds one of the largest index values ​​i1 (in... Figure 3 In the embodiment where the largest first index value i1 is 3, the data processor 13 uses a lookup table corresponding to the largest index value among these first index values ​​i1 (in Figure 3 In the embodiment, image frames are processed by looking up table LT3.

[0023] In some embodiments, the number of compensation operations included in each lookup table LT1-LT3 is limited, therefore, when the number of detected image frame repetitions exceeds one of the largest index values ​​i2 (in Figure 3 In the embodiment where the largest first index value i2 is 3, the data processor 13 uses a lookup table corresponding to the largest index value among these second index values ​​i2 (in Figure 3 In the embodiments, image frames are processed by compensation operations (MC13, MC23 or MC33).

[0024] In some embodiments, the data processor 13 processes B1, B2, and B3 according to the compensation operation MC33. Please refer to [further details]. Figure 3 When the value of the first index value i1 is N, the corresponding compensation operations each include N operation coefficients. The data processor 13 uses the N operation coefficients to process the image data of the image frames received at each of the N time points. For example, the data processor 13 uses the three operation coefficients in the compensation operation MC33 to process B1, B2, and B3 received at three different time points.

[0025] In other embodiments, the data processor 13 processes only B3 in accordance with the compensation operation MC33. In alternative embodiments, the data processor 13 processes only B2, B3 in accordance with the compensation operation MC33.

[0026] In the prior art, when the rhythm of the image signal is known, the display system only provides a fixed adjustment mode, such as the frame insertion operation, to the image signal. However, when the rhythm of the image signal changes or frequently switches such that the situation as if there is no rhythm occurs, the display system still uses the fixed adjustment mode to process the image signal. In this case, the processed image signal is prone to have a dropped frame state (such as the situation shown by the dashed box in the right half of FIG. 1) in which the data of some frames is covered. Therefore, watching such a signal will result in a larger stutter or skip. Figure 4

[0027] Compared with the prior art, the embodiments of the present application detect the repetition number of each image frame in the image signal SV, and then select a corresponding compensation operation in accordance with the repetition number of each group of image frames having the same image data to generate a compensated display signal SD. Because the selected compensation operation corresponds to the repetition number of the fast switching in the image signal SV, the display signal SD is smoother and continuous (such as the situation shown in the left half of FIG. 2), has less stutter, and has better viewing quality. Figure 4

[0028] That is, the image processing scheme provided by the present application can regard the image frames having the same image data and appearing continuously as a group of image frames, and determine a lookup table related to the compensation operation in accordance with the number of the image frames appearing continuously in the group of image frames. Next, the image processing scheme provided by the present application can select a group of compensation operations from the lookup table in accordance with the number of the image frames appearing continuously in another group of image frames next to the group of image frames, and adjust the image data of at least one image frame in the group of image frames based on the selected group of compensation operations.

[0029] Reference is made to Figure 5 . Figure 5 a flowchart of an image processing method 50 in some embodiments of the present application. In some embodiments, the image processing apparatus 10 of FIG. 1 utilizes the image processing method 50 to process the image signal SV. More specifically, the image processing apparatus 10 of FIG. 1 utilizes the image processing method 50 to increase the smoothness of the output display signal SD. The image processing method 50 includes steps S51, S52, and S53. For ease of understanding, the reference signs in FIG. 1 are used to describe the image processing method 50. In addition, the image processing method 50 is not limited to steps S51-S53. In further embodiments, the image processing method 50 also includes steps S54 and S55. Figure 1 Figure 1 Figures 1 to 3 Figures 1 to 3 ​​​​​The image processing apparatus 10 and the steps described above in the operation of the image processing apparatus 10.

[0030] In step S51, the image frame input sequence (such as...) is detected. Figure 2 The sequence of consecutive occurrences of each image frame in A1-A2, B1-B3, C1-C3, and D1-D2 is defined as follows: the number of times each image frame appears consecutively, where the image frame input sequence includes at least one first image frame (e.g., B1-B3) and at least one second image frame (e.g., C1-C3) input sequentially, and the image data of each first image frame is different from the image data of each second image frame. In step S52, a first lookup table (e.g., lookup table LT3) is determined based on the first occurrence count of the at least one first image frame, and the first lookup table indicates multiple sets of compensation operations (e.g., MC31, MC32, and MC33). In step S53, a first set of compensation operations (e.g., MC33) is used from the multiple sets of compensation operations based on the second occurrence count of the at least one second image frame to process the image data of the at least one first image frame.

[0031] The foregoing description of this specification briefly outlines the features of certain embodiments of the present invention, enabling those skilled in the art to more fully understand the various implementations of the invention. Those skilled in the art should understand that they can readily use the present invention as a basis to design or modify other processes and structures to achieve the same objectives and / or advantages as the embodiments described herein. Those skilled in the art should understand that these equivalent implementations still fall within the spirit and scope of the present invention, and various variations, substitutions, and modifications can be made without departing from the spirit and scope of the present invention.

[0032] Explanation of reference numerals in the attached figures:

[0033] 10: Analog-to-Digital Converter

[0034] 11: Detector

[0035] 12: Registers

[0036] 13: Data Processor

[0037] 131: Memory

[0038] 14: Monitor

[0039] SV: Image signal

[0040] SD: Display signal

[0041] A1: Image Frame

[0042] A2: image frame

[0043] B1: image frame

[0044] B2: image frame

[0045] B3: image frame

[0046] C1: image frame

[0047] C2: image frame

[0048] C3: image frame

[0049] D1: image frame

[0050] D2: image frame

[0051] N1: storage unit

[0052] N2: storage unit

[0053] N3: storage unit

[0054] N4: storage unit

[0055] LT1: lookup table

[0056] LT2: lookup table

[0057] LT3: lookup table

[0058] i1: first index value

[0059] i2: second index value

[0060] MC11: compensation operation

[0061] MC12: compensation operation

[0062] MC13: compensation operation

[0063] MC21: compensation operation

[0064] MC22: compensation operation

[0065] MC23: compensation operation

[0066] MC31: compensation operation

[0067] MC32: compensation operation

[0068] MC33: compensation operation

[0069] 50: image processing method

[0070] S51: step

[0071] S52: step

[0072] S53: Step

Claims

1. A method for processing images, comprising: detecting a number of consecutive occurrences of each image frame in a sequence of image frames to determine a rhythm of the sequence of image frames, wherein the sequence of image frames comprises a plurality of first image frames and a plurality of second image frames inputted in sequence, image data of each first image frame being different from image data of each second image frame; determining a first lookup table according to a first number of consecutive occurrences of the plurality of first image frames, the first lookup table indicating a plurality of sets of compensation operations; and selecting a first set of compensation operations from the plurality of sets of compensation operations of the first lookup table according to a second number of consecutive occurrences of the plurality of second image frames to process image data of the plurality of first image frames, wherein detecting the number of consecutive occurrences of each image frame in the sequence of image frames to determine the rhythm of the sequence of image frames comprises: sequentially measuring average luminance of each image frame; and determining whether each two adjacent image frames are two adjacent image frames having the same image data according to the average luminance of each of the two adjacent image frames. The first number is N, the first set of compensation operations comprises N operation coefficients, and processing the image data of the plurality of first image frames comprises:

2. The method of claim 1, wherein, using the N operation coefficients to respectively process image data of the plurality of first image frames received at N time points. Determining the first lookup table according to the first number of consecutive occurrences of the plurality of first image frames comprises:

3. The method of claim 1, wherein, providing a plurality of lookup tables, wherein the plurality of lookup tables respectively correspond to different first index values; and selecting the first lookup table from the plurality of lookup tables according to the first number, wherein a first index value of the first lookup table matches the first number. Selecting the first lookup table from the plurality of lookup tables according to the first number comprises:

4. The method of claim 3, wherein, when the first number reaches a maximum index value in the first index values, selecting a lookup table corresponding to the maximum index value as the first lookup table. Using the first set of compensation operations to process the image data of the plurality of first image frames according to the second number of consecutive occurrences of the plurality of second image frames comprises:

5. The method of claim 1, wherein, providing a plurality of sets of compensation operations, wherein the plurality of sets of compensation operations respectively correspond to different second index values; and selecting the first set of compensation operations from the plurality of sets of compensation operations according to the second number, wherein a second index value of the first set of compensation operations matches the second number.

6. An apparatus for processing images, comprising: a detector configured to detect a number of consecutive occurrences of each image frame in a sequence of image frames to determine a rhythm of the sequence of image frames, wherein the sequence of image frames comprises a plurality of first image frames and a plurality of second image frames inputted in sequence, image data of each first image frame being different from image data of each second image frame; and a processor configured to determine a first lookup table according to a first number of consecutive occurrences of the plurality of first image frames, the first lookup table indicating a plurality of sets of compensation operations, and to select a first set of compensation operations from the plurality of sets of compensation operations of the first lookup table according to a second number of consecutive occurrences of the plurality of second image frames to process image data of the plurality of first image frames. A data processor is configured to determine a first lookup table according to a first number of consecutive occurrences of the first image frames, wherein the first lookup table indicates a plurality of sets of compensation operations, and the data processor is further configured to select a first set of compensation operations from the plurality of sets of compensation operations of the first lookup table according to a second number of consecutive occurrences of the second image frames, to process image data of the first image frames, wherein detecting the number of consecutive occurrences of each image frame in the image frame input sequence to determine the rhythm of the image frame input sequence comprises: sequentially measuring an average brightness of each image frame; and determining whether each two adjacent image frames have the same image data according to the average brightness of each two adjacent image frames.

7. The image processing apparatus of claim 6, wherein: when the first number of consecutive occurrences is N, the first set of compensation operations includes N operation coefficients, and the data processor is configured to use the N operation coefficients to process image data of the first image frames received at N time points, respectively.

8. The image processing apparatus of claim 6, wherein: the data processor includes a memory configured to store a plurality of lookup tables, wherein the plurality of lookup tables correspond to different first index values, respectively, and the data processor is further configured to select the first lookup table from the plurality of lookup tables according to the first number of consecutive occurrences, wherein a first index value of the first lookup table matches the first number of consecutive occurrences.

9. The image processing apparatus according to claim 8, wherein when the first number of consecutive occurrences reaches a maximum index value in the first index values, the data processor is configured to select a lookup table corresponding to the maximum index value as the first lookup table.

10. The image processing apparatus of claim 6, wherein: the first lookup table is configured to provide a plurality of sets of compensation operations, wherein the plurality of sets of compensation operations correspond to different second index values, respectively, and the data processor is further configured to select the first set of compensation operations from the plurality of sets of compensation operations according to the second number of consecutive occurrences, wherein a second index value of the first set of compensation operations matches the second number of consecutive occurrences.

Images